Textile recycling

Since 2000, global apparel production and sales have nearly doubled. Rapid collection changes and the increase in e-commerce are accelerating this development. Currently, used textiles are largely destroyed, and further recycling is the exception: only one percent of all textiles are recycled and returned to the cycle. Through the use of innovative processes, this rate could be significantly increased.

So there is a lot to be said for recycling textiles in a circular fashion. However, this is easier said than done. One major challenge, for example, is that many garments consist not only of one or more materials, but of fiber mixtures. Innovative processes are needed to successfully recycle these end-of-life garments. New technologies such as artificial intelligence or approaches such as Life -Cycle Assessments (LCA) can support this. In addition, recycling is a holistic process across the entire value chain. This needs to be considered especially when upcycling.

Innovative approaches from the field

Some companies and institutes are already working on new approaches to optimize recycling processes. One example is the EU-funded project on the mechanical recycling of used clothing. Together with a consortium of partner companies, the company imat-uve developed a mechanical recycling process that prepares waste textiles made of mixed fibers in such a way that they can be used in vehicle interiors, for example. "Previous recycling approaches mostly follow chemical processes and therefore cannot be seen in terms of true sustainability," imat-uve explains in a press release. Optimizations to the recycling process allow the blended fibers to be very finely shredded and processed into a soft uniform card sliver using new spinning preparation technologies. This forms a good basis for spinning. The resulting yarns (Nm15 and Nm28) can be further processed for different requirements, depending on the admixture of polyester.

Another innovative approach is evident in the area of recycling cotton clothing. Recycling clothing made from cotton has been a major technical challenge until now, as it is rarely single-grade. A team of researchers from the Fraunhofer Institute for Applied Polymer Research IAP, together with the Swedish company re:newcell, has succeeded for the first time in producing a viscose filament yarn from recycled cotton (Learn more: A T-shirt made from old jeans). Normally, pulp is used by the textile industry as a feedstock to make man-made regenerated cellulose fibers such as viscose, modal or lyocell. Since cellulose is not fusible, it must be dissolved into a spinning solution and transformed into cellulosic staple fibers. "However, we received pulp sheets made from recycled cotton from re:newcell and were asked to see if they could be processed into viscose fibers. By setting the right parameters in the dissolving as well as spinning process, such as effective filtration stages, we were able to dissolve out the foreign fibers contained in the pulp," explains Dr. André Lehmann, head of the Fiber Technology department at Fraunhofer IAP.

Progress is not only needed in the field of mechanical or chemical recycling, but already in the categorization and sorting of fibers. Among others, the Berlin-based start-up circular.fashion is dedicated to this challenge. The company has developed the so-called circularity.ID, a kind of chip that can be integrated into the label, for example, and contains information about the garment, such as the materials used or recycling options. According to circular.fashion, this enables the targeted sorting of used clothing and makes the subsequent recycling process a little easier.